Opentracing is one of the open protocol for distribute tracing between microservices. With APM, it helps to identify service dependency and target bottom-neck during performance tuning. Even it merged to OpenTelmetry in recent years but it still popular for APM.

This demo will show how to add custom trace in Java project. It will add to Aspect to fire in each method.

Prerequisites

Project has been connected to APM;

Check opentracing dependencies added in project.

dependencies {
    implementation 'co.elastic.apm:apm-opentracing:1.+'
    implementation 'io.opentracing:opentracing-api:0.+'
}

Steps

Add custom trace.
Add code in method required to block in span.

import co.elastic.apm.opentracing.ElasticApmTracer;
import io.opentracing.Scope;
import io.opentracing.Span;
import io.opentracing.Tracer;
import io.opentracing.log.Fields;
import io.opentracing.tag.Tags;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.util.HashMap;
import java.util.Map;

@Aspect
@Component
public class LoggingAspect {
    private static final int LOG_LEVEL_WARNING_THRESHOLD =5000;

    private Tracer tracer = new ElasticApmTracer();

    @Around("execution(*!execution(* org.jooq..*(..))")
    public Object profileAllMethods(ProceedingJoinPoint proceedingJoinPoint) throws Throwable {
        MethodSignature methodSignature = (MethodSignature) proceedingJoinPoint.getSignature();

        //Get intercepted method details
        String className = methodSignature.getDeclaringType().getSimpleName();
        String methodName = methodSignature.getName();
        String methodFullName=className+"."+methodName;

        Object result=null;

        Span span= tracer.buildSpan(className+"#"+methodName).start();
        try (Scope scope = tracer.scopeManager().activate(span)) {
            result = proceedingJoinPoint.proceed();
        } catch(Exception ex) {
            Tags.ERROR.set(span, true);
            Map<String, Object> spanErrorLog=createErrorSpan(ex);
            span.log(spanErrorLog);
        } finally {
            span.finish();
        }
        return result;
    }

    private Map<String, Object> createErrorSpan(Exception ex) {
        Map<String, Object> spanErrorLog=new HashMap<>();
        spanErrorLog.put(Fields.EVENT, "Error");
        spanErrorLog.put(Fields.ERROR_OBJECT, ex);
        spanErrorLog.put(Fields.MESSAGE, ex.getMessage());
        return spanErrorLog;
    }
}